Liquid products such as soft drink syrup or chemical products are often shipped in small volumes such as five gallon portions. These liquid volumes may be packaged in a plastic bag and housed within a paperboard container to protect the bag from puncture or compression. This method of packaging is often referred to as "bag in box." The bag is often provided with a fitment or a spout and the box with a corresponding access door to allow access to the contents of the bag through a wall of the box.
Prior boxes that have been specially designed to enclose and transport these five gallon bags usually are six sided boxes folded from a single sheet of corrugated paper that is folded and glued along a single glue lap to an outside wall of the box. The boxes usually have bottom and top walls that are formed from the overlap of major and minor flaps, and the box usually folds flat for storage. The boxes also have a perforated section along an end wall that may be removed to accommodate the spout so that liquid may be removed from the bag without opening the top of the box.
However, these prior boxes have presented several problems to manufacturers and distributors. For example, distributors have discovered that these boxes have insufficient structural support and that movement of the liquid filled bag within the box may cause the box to unfold or breakdown during warehousing and distribution. Further, the boxes have inadequate stacking strength and may crush, or have its perforated spout break out or the box may otherwise be damaged under the weight of a palletized load. In more serious cases where the perforated spout breaks out a tear forms in a side or end panel of the box which follows the paperboard corrugations causing the box to rip open. In all cases, the box is rendered incapable of protecting the contents of the bag from outside hazards that may puncture the bag and release its contents.
Manufacturers and distributors have also encountered problems with this box. For example, the glue lap that was provided to hold prior boxes together, oftentimes became unglued during the loading of the box with a liquid filled bag causing the entire box to unfold. Further, the manufacturers have had difficulty in detecting leaks in these boxes until after the boxes have been filled and prepared for shipment or actually shipped. Manufacturers have also had difficulty, in loading the prior boxes, to get the liquid filled bags to cover the entire bottom of the box for even weight distribution.
Improvements have been made to the single piece containers by constructing a container from three separate pieces of corrugated paperboard. An example of such a container is disclosed in U.S. Pat. No. 5,143,278 which is assigned to the owner of the present invention and is incorporated herein by reference. The '278 Patent discloses a top loaded container which has reinforcing flanges that add considerable support to the container far in excess of single piece boxes. However, even the container disclosed in the '278 Patent must be stacked on a pallet with each box in conformation with the lower box, that is sidewall over sidewall and end wall over end wall, in a column stacking pattern to avoid damaging the container on panels 32 and 36 between side flanges 120.
For these reasons, it is desirable to produce a more cost effective box for shipping liquid filled bags, that has greater stacking strength than boxes presently being used so that the boxes may be stacked on a pallet in an interlocking fashion, that is one box may be placed transverse to a lower box, or shipped in single increments by common courier such as U.P.S.